Keithley 4200-SCS Reference Manual page 422

Section 6: Keithley Interactive Test Environment (KITE)
EXPFITA: Formulator function
Purpose
Format
Example
Remarks
EXPFITB: Formulator function
Purpose
Format
Example
Remarks
6-296
Performs an exponential fit as follows:
• Fits the following exponential relationship to a specified range of values in two
columns (vectors)—one column, VX, containing X values and the other column, VY,
containing Y values:
(EXPFITB * X)
Y = EXPFITA * e
• where EXPFITA and EXPFITB are fit constants.
• Returns the value of the constant EXPFITA in the relationship above.
EXPFITA(VX, VY, STARTPOS, ENDPOS)
Where: VX = The name of any column (vector) listed under Columns.
VY = The name of any column (vector) listed under Columns.
STARTPOS = For the range of X and Y values to be exponentially fitted, the
row number (index) of the starting values.
ENDPOS = For the range of X and Y values to be exponentially fitted, the row
number (index) of the ending values.
DIODEOFFSET = EXPFITA(ANODEV, ANODEI, 2, LASTPOS(ANODEV))
If a VX or VY value at either STARTPOS or ENDPOS is an invalid number (that is, the
value is #REF), the function will not return a valid result.
Performs an exponential fit as follows:
• Fits the following exponential relationship to a specified range of values in two
columns (vectors)—one column, VX, containing X values and the other column, VY,
containing Y values:
(EXPFITB * X)
Y = EXPFITA * e
• where EXPFITA and EXPFITB are fit constants.
• Returns the value of the constant EXPFITB in the relationship above.
EXPFITB(VX, VY, STARTPOS, ENDPOS)
Where: VX = The name of any column (vector) listed under Columns.
VY = The name of any column (vector) listed under Columns.
STARTPOS = For the range of X and Y values to be exponentially fitted, the
row number (index) of the starting values.
ENDPOS = For the range of X and Y values to be exponentially fitted, the row
number (index) of the ending values.
DIODEIDEALITY = 1/(EXPFITB(ANODEV, ANODEI, 2,
LASTPOS(ANODEV))*0.0257)
If a VX or VY value at either STARTPOS or ENDPOS is an invalid number (that is, the
value is #REF), the function will not return a valid result.
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Model 4200-SCS Reference Manual
4200-901-01 Rev. S / May 2017